Conventional integrated circuit imaging devices include an array of light detecting elements or pixels which are interconnected to generate a signal representation of an image illuminating the device. Common examples of conventional integrated circuit imaging devices are a charge coupled device (CCD) and a complementary metal oxide semiconductor (CMOS) image sensing device and Focal Plane Arrays (FPA). Such integrated circuits employ a pixel, such as a photodiode or phototransistor, that is capable of conducting current approximately proportional to the intensity of the light illuminating the element and a charge storage element. The collection of the signals from the pixels represents the image of a scene viewed by the array.
Each pixel represents a sample of the scene and hence is a data value in the two-dimension image produced by the imaging system. Defective pixels, commonly referred to as “bad pixels,” are caused by an array defect and do not provide the correct light intensity value. Bad pixels appear as image artifacts that can reduce the image quality significantly. In particular, a bad pixel produces an output signal that significantly deviates from the mean output level of adjacent pixels when the exposure level of all pixels is uniform.
The defective pixels are typically distributed in a random manner. In some situations, the defective pixels may be clustered together. A “bad column” of adjacent defective pixels or a “bad row” of adjacent defective pixels, however, may also occur.